This invention relates generally to medical devices and methods for delivering a biologically active material to a desired location within the body of a patient. More particularly, the invention is directed to medical devices having a catheter and a balloon with a plurality of micro-needles at its outer surface for delivering a biologically active material to a body lumen. Additionally, the invention is directed to medical devices having a catheter, a balloon and a sheath surrounding the balloon. Also, the invention is directed to medical devices having a catheter, a balloon and a shockwave generator for delivery of biologically active materials.
When a disease is localized to a particular part of the body, in particular a body lumen, such as, without limitation, a blood vessel, direct administration of biologically active materials for the treatment of the disease may be more preferred than systemic administration. Systemic administration requires larger amounts and/or higher concentrations of the biologically active materials because of inefficiencies associated with the indirect delivery of such materials to the afflicted area. Also, systemic administration may cause side effects which may not be a problem when the biologically active material is locally administered.
However, such localized delivery of biologically active materials to a body lumen is difficult since body luniens are involved in the transport of body fluids, which tend to carry the biologically active material away from the afflicted area. Thus, there is a need for devices and methods for the localized delivery of biologically active materials to afflicted tissue, especially body lumens.
A number of devices for delivering biologically active materials to body lumens or vessels involve the use of catheters having expandable portions, such as a balloon, disposed on the catheter. To overcome the problem that the delivered biologically active material is washed away from the applied area by the blood-flow, there are generally two kinds of prior art balloon catheters: one kind is a balloon catheter which temporarily occludes blood-flow and infuses a biologically active material to the occluded area, and the other kind is a balloon catheter which directly administers the biologically active material to a vessel-wall by the use of macro-needles. However, the former still has the problem of systemic leakage around the balloon, allowing for systemic distribution of the biologically active material. On the other hand, although the latter type of balloon catheters do not cause significant systemic leakage of the biologically active material, because of the large size of the macro-needles used to inject the biologically active material into the tissue, there is still back-leakage at the needle track. Also, the large size of the needles cause damage in the tissue of the vessel wall. Thus, the prior art balloon catheters cannot deliver a biologically active material quickly and accurately to a wall of body lumen without causing damage in the body lumen tissue and/or systemic leakage.
In addition, rapid advances in DNA technologies have increased the necessity for a device or method which realizes more accurate and uniform delivery of genetic materials. Therefore, there is still a need for devices and methods which cause minimum tissue damage while ensuring accurate and uniform localized delivery of biologically active materials including genetic materials to body lumens.
These and other objectives are accomplished by the present invention. To achieve the aforementioned objectives, we have invented a medical apparatus and a method for delivery of a biologically active material to a surface of a body lumen.
The apparatus for delivery of biologically active materials of the invention comprises a catheter and a balloon having micro-needles.
In an embodiment of the invention, the apparatus comprises a catheter, a balloon, with a biologically active material disposed on an outer surface of the balloon, and micro-needles disposed upon the outer surface of the balloon. The micro-needles contact a body lumen as the balloon is expanded, and the biologically active material is delivered into the body lumen. The biologically active material can be delivered by fluid convection along the outer surface of the micro-needles. Alternatively, biologically active material can, instead of being disposed on the outer balloon surface, be expelled from an inner compartment of the balloon through pores in the outer balloon surface. The balloon is optionally surrounded by a sheath.
In another embodiment of the invention, the apparatus comprises a catheter having at least one lumen in fluid communication with an internal compartment of the balloon, and micro-needles having a lumen in fluid communication with the compartment, wherein the micro-needles are disposed upon an outer surface of the balloon. The micro-needles contact a body lumen as the balloon is expanded, and the biologically active material is delivered to the body lumen through the micro-needle lumen. The balloon is optionally surrounded by a sheath.
Further, another embodiment of the apparatus of the invention comprises a catheter, a balloon disposed upon the catheter, and a shockwave generator for delivery of a biologically active material.
Moreover, in another embodiment, the apparatus of the invention comprises a catheter, a balloon having micro-needles disposed upon or within an outer surface of the balloon, and a triggering source for rupturing the micro-needles. The micro-needles are ruptured by the triggering source, which can be a shockwave, and a biologically active material is delivered through the micro-needles to an afflicted area of a body lumen.
The present invention also includes a method for delivering a biologically active material to a body lumen. In one embodiment, the method is carried out by inserting a catheter with a balloon disposed thereon into a body lumen. The balloon has micro needles disposed upon or within its outer surface. Once the catheter is inserted, the balloon is inflated so that the micro-needles contact the surface of the body lumen. The biologically active material is then delivered to the surface of the body lumen.
In another embodiment, the method of the invention involves inserting a catheter having a balloon disposed upon it into a body lumen. The balloon is inflated to contact a body lumen. A shockwave is then applied to the afflicted area of the body lumen to allow delivery of the biologically active material into the body lumen.